The technical scope of the present invention is that of oscillating mass equilibrating systems, such as, for example, a piece of artillery mounted on a top carriage.
When a piece of artillery is mounted on a fixed or mobile top carriage, it needs to be oriented vertically according to the required firing conditions. This is usually carried out by a known laying device. When the propelling charge of the munition is initiated, the oscillating mass (barrel, breech block, etc.) recoils causing an unbalance that must be counteracted.
Equilibrating systems arranged between the top carriage and the oscillating mass are known. These systems generally include a spring or a nitrogen chamber that is arranged so that the pressure exerted by the nitrogen or the spring is opposed to the force exerted by the oscillating mass. The principal function of the equilibrating system is to counteract the strain created by the mass of the barrel to facilitate the laying operations of the gun.
In the device described in the document entitled "Cours de materiel d'artillerie", Rivals, 1955, a spring-based or gas-based equilibrator that does not take elevation laying into account is disclosed. A spring that is placed under tension after reaching a certain angle causes a abrupt change in the equilibrating curve gradient.
In the document entitled "US MIL SPECS" dating from 1990 and published by the U.S. Army, the equilibration is carried out by a nitrogen chamber. Calculations are made by studying the moment generated by the equilibrator (i.e., by observing the variation of the force and the position of a lever crank). The correction of the curve according to the external temperature is carried out by a pump that rebalances the initial pressure and by varying the length of the lever crank to change the equilibration moment at each laying angle.
In European Patent EP-A-309 646, the equilibrating pressure is adjusted by a valve according to the external temperature.
The main disadvantage of all known systems lies in the fact that the laying and equilibrating are carried out by independent systems. The resulting device is both cumbersome and very complicated because special connections must be provided for each of the two systems. Moreover, the spring used for the abrupt change in the equilibrating curve gradient must be specially manufactured and therefore is costly.